Philosophical Principles on Matter and Movement, Denis Diderot

Avertissement
du Traducteur - December 2010

This is my rendering into English
of Denis Diderot's sketch (1770) of a materialist philosophy
built upon discursive moves away from conceiving force as
acting upon particles rather than coming from particles
themselves. This conception goes further than previous
philosophical programs in offering a vision that adequately
removes teleology from physics, even if it still includes
purpose in the material world by giving this world its own
sufficient laws.

With this impetus then, who is to
say how many forces there are in the universe? Indeed, a
hurricane fills air with power, heating a tube of glass makes
gold leaves flutter - so why not conceive of a plurality of
forces in the universe rather than gravity alone? Perhaps such
a view paves the way for a scientific poetics in that each new
presentation of scientific findings is not one more triumph in
the modern labor of describing the nth-millionth variation on
gravitation. Even a new scientific model that seems destined to
only raise Newton above the shoulders of others might be
understood as emerging from very particular crumbs from which
it had previously been destined to be elevated only by
Newtonian Gravity.

NOTE: This is a translation made
more for the purpose of familiarizing myself with Diderot's
text. It is updated often, especially when insights about how
to render certain passages strike me. I also hope to offer a
"reading" in the form of annotations/footnotes soon.

I don't know in what sense philosophers have supposed that
matter has been indifferent to movement and to rest. What is
very certain is that all bodies gravitate upon each other, that
all particles of bodies gravitate upon each other, that in this
universe, all is in translation or endeavor (nisu), or
in translation and in endeavor (in nisu) at once.

This supposition of philosophers resembles those of
geometers who admit points without any dimension, lines without
length or depth, surfaces without thickness, or perhaps they
speak of rest of one mass relative to another. Everything is in
relative rest in a vessel beaten by a storm. Nothing is in
absolute rest, not even aggregate molecules, nor this vessel,
nor the body that it encloses.

Even if they do not conceive of a tendency to rest more
than movement in any body, they look at matter as homogenous.
They make an abstraction from all of its essential qualities;
they consider it inalterable in the instant almost indivisible
from their speculation. They leap from relative rest of one
aggregate to another aggregate; they forget, while proceeding
from the inertness of a body to movement or to rest, that a
block of marble tends toward its dissolution. They annihilate
matter with thought and generalized movement that animates all
bodies, and a particular action of one upon another, which
destroys them all. This is how inertness, false in itself, is
but temporary, and has not made laws of movement erroneous.

The body, according to some philosophers, is
in itself, without action and without force. This is a
terrible falsity, quite contrary to all valid physics, to all
valid chemistry. By itself, by the nature of its essential
qualities, whether considered as a molecule or as a mass, it is
full of action and force.

For you to represent movement, they add, in
addition to existing matter, it is necessary for you to
imagine a force which should act on this matter. Not so. A
molecule endowed with but one quality for its nature is an
active force in itself. It exercises itself upon another
molecule, exercised upon it. All these paralogisms maintain the
false supposition of homogeneous matter. You who imagine matter
at rest just the same, can you imagine fire at rest? Everything
in nature has a different action, as does this heap of
molecules you call fire. In this heap you call fire, each
molecule has a nature, an action.

Here is the true difference between rest and movement:
absolute rest is an abstract concept that does not exist in
nature, and movement is a quality as real as length, width, and
depth. Am I concerned with what you think? Do I hope you look
at matter as homogeneous or heterogeneous? Do I expect that,
creating an abstraction of its qualities and only considering
its existence, you see it in rest? Do I care that you search,
as a result, for one cause that moves it? Do what you please
with geometry and metaphysics. Yet, I who am a natural
scientist and chemist, who works with bodies in nature and not
from my head, I see them existing, varied, adorned by
properties and actions and acting in the universe as in the
laboratory - where one spark is no longer found beside three
molecules combined with saltpeter, carbon, and sulfur, without
a necessary explosion following.

Gravity is not a tendency to rest, it is a tendency to
local movement.

So that matter may move, it is said further, that an
action, a force is necessary. Yes, a force external to the
molecule, or inherent to, essential to, or engaged with this
molecule, constituting its nature from an igneous, aqueous,
nitrous, alkaline, or sulfurous molecule. Regardless of this
nature, force results, with action from it outside of it, and
action of other molecules upon it.

Force acting on a molecule exhausts itself. Inner
force of the molecule does not. It is immutable, eternal. These
two forces can produce two types of endeavors (nisus).
The first, endeavor (nisus) that ends; the second,
endeavor (nisus) that never ends. It is therefore
absurd to say that matter has a real opposition to movement.

Quantity of force is constant in nature, but the sum of
endeavors (nisus) and the sum of translations are
variable. The greater the sum of endeavors (nisus),
the smaller the sum of translations; the greater the sum of
translations, the smaller the sum of endeavors (nisus).
The incineration of a city suddenly grows the sum of
translations with a prodigious quantity.

One atom moves the world. Nothing is more true - except
an atom moved by the world. Since the atom has its own force,
it cannot be without effect.

As a natural scientist we must never say, "a body is
a body", because we are no longer doing natural science.
This is to make abstractions that lead to nothing.

We must not confound action with mass. There can be great
mass and small action. There can be small mass and great
action. One molecule of air might shatter a block of steel.
Four grains of powder are sufficient for dividing a rock.

Yes, without a doubt, when an homogeneous aggregate is
compared to another aggregate of similar homogeneous matter,
when we speak of action and reaction of these two aggregates,
their relative energies are in direct relation to mass. But
when it is a matter of heterogeneous aggregates, there are no
longer the same laws. There are as many different laws as there
are varieties of force intertwined with each elementary
molecule and constitutive of bodies.

The body is resistant to horizontal movement. What
does that mean? It is well known that there is a force general
and common to all molecules of the globe we inhabit, a force
which pushes against bodies according to a certain
perpendicular direction, or much the same, along the surface of
the globe. But this general and common force is contradicted by
a hundred thousand others. Heating a tube of glass makes gold
leaves flutter. A hurricane fills air with power. Heat
volatilizes water; volatilized water carries with it, molecules
of salt. While this mass of bronze weighs against the ground,
air acts on it, changing its initial surface into a metallic
chalk, beginning the destruction of this body. What I say of
masses must be understood of molecules also.

Every molecule must be considered as currently animated
by three types of actions: the action of gravity or
gravitation, the action of its force intertwined with its
water, fire, air, sulfur nature, and the action on it of all
other molecules. It could also be that these three actions
would be convergent or divergent. Convergent, then the molecule
is endowed with its strongest possible action. In order to give
an idea of the greatest possible action, it would be necessary
to thus say, to give a bunch of absurd suppositions, to place a
molecule in a totally metaphysical situation.

How can one say that a body resists more through movement the
greater its mass? Not in the sense that the more its mass is
great, the more its pressure against an obstacle is weak. No
daily laborer (crocheteur) knows the contrary. It's
only relative to one direction opposite its pressure. In this
direction, it is certain that it resists as much through its
movement the greater its mass. In the direction of gravity,
it's not less certain that its pressure or force, or tendency
to movement, grows in relation to its mass. What then does all
this signify? Nothing.

I am surprised to see a body fall no more than to see flame
raise itself up, or to see water act all over and to weigh in
on its height and its base in such a way that with a mediocre
quantity of fluid, I can break the most solid vessels, just as
one sees expanding steam dissolve the hardest bodies in Papin's
machine, and raise the heaviest bodies in a pneumatic machine (la
machine à feu). But I fix my eyes on the universal mass of
bodies: I see everything in action and reaction; everything
being destroyed under one form, everything being recomposed
under another: sublimations, dissolutions, combinations of all
types, phenomena incompatible with a homogeneity of matter,
from which I conclude that it is heterogeneous, that an
infinity of different elements exist in nature, that each of
these elements by its diversity has its individual force,
innate, immutable, eternal, indestructible, and that these
interconnected forces in the body have actions outside of the
body, from which arises movement, or rather universal
fermentation in the universe.

What do the philosophers of whom I refute here, the errors and
paralogisms, do? They attach themselves to a single and unique
force, perhaps, common to all the molecules of matter; I say, perhaps,
because I would not be surprised if there should be in nature,
such a molecule which, joined to another, rendered the
resulting mixture lighter. Always in the laboratory, an inert
body is volatilized by an inert body. And when those who
consider all action in the universe only as that of
gravitation, in having inferred inertness from matter to rest
or movement, or rather, the tendency of matter to rest, they
believe to have resolved the question, when they have not even
grazed it.

When the body is viewed at as more or less resistant, and not
as weighing or tending towards a center of graves(1), a force may already be
recognized, an inner, intertwined action. It has many others
however, among which some exert themselves all over, and others
take particular directions.

The supposition of a any kind of being placed outside the
material universe is impossible. We must never suppose
likewise, because one can never infer anything from such
suppositions.

Everything said of the impossibility of the growth of
movement or of speed, proceeds by descent against the hypothesis of
homogenous matter. But what is this fact to those who infer
movement in matter, from its heterogeneity? The supposition of
a homogenous matter is strongly subject to other absurdities.

If one insists not on considering things in one's head,
but in the universe, one will convince oneself by the diversity
of phenomena, the diversity of elementary matter, the diversity
of forces, the diversity of actions and of reactions, the
necessity of movement. And for all these accepted truths, one
says no more, "I see matter as existing; I see it first of
all at rest"; because one will sense that this is to make
an abstraction from which one can conclude nothing. Existence
draws along neither rest nor movement; but existence is not the
only quality of rest.

All natural scientists who suppose matter indifferent to
movement and to rest, have no clear ideas of resistance. In
order that they may conclude something of resistance, it would
be necessary that this quality should be exercised
indistinctly, all over, and that its energy were equal in every
direction. This would then be an inner force, like that of
every molecule, but this resistance varies to the same degree
that there are directions in which the body can be pushed. It
is greater vertically than horizontally.

The difference between gravity and the force of inertia:
gravity does not equally resist, in all directions, but
instead, the force of inertia resists equally, in all
directions.

And why would the force of inertia not bring about the
effect of retaining the body in its state of rest and in its
state of movement, and by the sole notion of resistance
proportioned to the quantity of matter[?] The notion of pure
resistance is applied equally to rest and to movement: to rest
when the body is in movement; to movement, when the body is in
rest. Without this resistance, there would be no shock before
movement nor would it be stopped after this shock, because the
body would be nothing.

In the experiment of the ball suspended by a thread,
gravity is destroyed. The ball pulls the thread, as much as the
thread pulls the ball. Thus the resistance of bodies comes from
a single force of inertia.

If the thread has pulled the ball more than gravity, the
ball would ascend. If the ball has been pulled more by gravity
than by the thread, it would descend. Etc. Etc.